It is often desirable to monitor the potential of different electrode in the battery. For instance, if the voltage of different electrodes is known, it is often possible to identify whether failure of a battery is being caused by the positive electrode or the negative electrode.
The voltage of the battery does not indicate the potential of different electrodes since the battery voltage is the difference between the potentials of the positive and negative electrodes. As a result, it has been proposed to incorporate a reference electrode into these batteries. A reference electrode has a known potential that stays substantially constant during the operation of the battery. The potential of a particular electrode in the battery can then be determined by measuring the voltage between the electrode and the reference electrode and comparing the measured voltage to the known potential of the reference electrode.
Current efforts to incorporate a reference electrode into a battery have inserted a wire or other structure between the positive electrodes and negative electrodes in the battery. However, when the electrodes are wound or stacked, these reference electrodes deform the electrodes causing an uneven distance between adjacent electrodes. The different distances for ions to travel between the electrodes causes the performance of the battery to be unpredictable.
For the above reasons, there is a need for an improved battery having a reference electrode.